Jafar is the main villain from Aladdin, and is one of the Organization's high-ranking officials.
In the first film, Jafar tries to find Genie's lamp in order to take over Agrabah as its new ruler, manipulating several people, including Aladdin, into finding it for him. Initially when Aladdin takes back the lamp from Jafar and becomes the Genie's master, he comes back to Agrabah pretending to be a rich prince called "Prince Ali" and Jafar doesn't know it is Aladdin until he spots Aladdin with the lamp and comes up with a plot to steal it after barely escaping arrest by the Sultan's guards. After successfully stealing it from Aladdin, he first wishes to become the sultan, and then the most powerful sorcerer in the world. Jafar tries to win Princess Jasmine's heart by offering to make her his beloved queen, but an angry Jasmine refuses. Frustrated, Jafar decides to use his third wish to have Jasmine to fall in love with him. The Genie tells Jafar that he cannot make someone fall in love. Jafar angrily orders him to, not seeing Aladdin when arguing with the Genie. Jasmine pretends to fall in love with Jafar and seduces him, but after their kiss, Jafar discovers Aladdin. After battling Aladdin using a series of puns made real by his magic, Jafar transforms himself into a giant cobra in an attempt to kill Aladdin. After wrapping his coils around the boy, Jafar begins squeezing the life out of him, but Aladdin slyly manipulates him into using his third and final wish to become an all-powerful genie in an attempt to rule the whole universe. The power-hungry Jafar is convinced that becoming a genie is the only way to have ultimate power (even though he would still be second to Genie, since the latter gave the former his power), and he falls for Aladdin's trap. Now transformed into a genie with unlimited powers but no free will, Jafar becomes trapped in his own lamp along with Iago, then tossed out into the desert by the Genie.
In the second film, Iago, sick of being ordered around, abandons Jafar and drops his lamp down a well. The now-genie Jafar is later released by Abis Mal, who finds his lamp in the well after being humiliated by Aladdin. After cunningly making Abis-Mal waste his first two wishes, Jafar threatens Abis into helping him exact revenge on Aladdin. His plan includes holding Jasmine, Abu, the Sultan, and the Carpet hostage (as well as confining Genie in a power orb to prevent him from foiling his plan) and forcing a reformed Iago to help him frame Aladdin for the Sultan's "death", which would cause him to face death at the hands of the palace guards. Luckily, Iago frees Genie from the orb, giving him enough time to save Aladdin and his friends. When Jafar discovers this, he opens up a volcanic fissure into the earth in an attempt to destroy Aladdin and the others and keep his lamp safe. Just as Iago grabs the lamp and attempts to give it to Aladdin to put an end to it, Jafar shoots the bird down with a fireball. Having heard from Genie that destroying the genie's lamp while a genie is bound to it will destroy the genie itself, an injured Iago manages to kick the lamp into the lava, melting it and causing Jafar to fade to a skeleton wreathed in electricity before imploding into a cloud of dust, destroying him for good. Jafar doesn't appear in the third film, but is mentioned once by Genie.
In an episode of Hercules: The Animated Series called "Hercules and the Arabian Night" Jafar makes another attempt at revenge, and is temporarily resurrected by Hercules's arch-enemy, Hades. He has lost his status as an all-powerful immortal genie after dying, but Hades gives him a new cobra staff that makes him flesh and blood as long as he holds it, and the two villains team up to get rid of Aladdin and Hercules. However, due to Aladdin's wit and Herc's strength, Jafar is defeated for the final time, being pulled into the River Styx.